Lathe chuck



Feb. 7, 1950 F. KRAEMER 2,496,545

LATHE CHUCK Filed Nov. 21, 1946 2 Sheets-Sheet l Feb. 7, 1950 F. KRAEMER 2,496,545

LATHE CHUCK Filed Nov. 21, 1946 2 Sheets-Sheet 2 Patented Feb. 7, 1950 UNITED STATES PATENT OFFICE LATHE CHUCK Fenton Kraemer, Marysville, Kans. Application Novemberll, 1946, Serial No. 711,293

2 Claims. (01. 82-33) This invention relates to lathe chucks.

An object of this invention is to provide a lathe chuck which is particularly designed for mounting in the tail stock and will automatically center the work, the work being firmly and rotatably clamped to the device.

Another object of this invention is to provide a centering chuck for the tail stock of a lathe which can be mounted in a conventional tail stock, taking the place of the center point, the chuck including automatically adjustable work gripping jaws for gripping and centering the work.

A further object of this invention is to provide a centeringchuck wherein a plurality of work clamping jaws are slidably carried by the body of the device and will automatically grip the work as the tail stock is moved toward the head stock, and will accurately center work of different diameters.

With the above and other objects in view, my invention consists in the, arrangement, combination and details of construction disclosed in the drawings and specifications, and then more particularly pointed out in the appended claims.

In the drawings,

Figure 1 is a detail side elevation of a lathe chuck constructed according to an embodiment of this invention.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1,

Figure 3 is a sectional view taken on the line 3-3 of Figure 2,

Figure 4 is a fragmentary enlarged sectional view taken on the line 4-4 of Figure 3,

Figure 5 is a detail front elevation of the law operator,

Figure 6 is a detail front elevation, broken away, of the jaw carrier,

Figure 7 is a detail front elevation of the chuck,

Figure 8 is a detail front elevation of the jaw carrier with the jaws and omitting the jaw partly operator.

Referring to the drawings, the numeral l designates generally an elongated tapered shank or spindle which is adapted to engage in the center point hole of a tail stock. The shank or spindle III has secured to or formed integral with the outer end thereof a cup-shaped housing H which is formed of an inner wall l2 and a cylindrical side wall H which is formed with threads ii. A cap i is threaded on the outer end of the housing II and is formed with a central opening it of relatively large size through which a round work piece ll is adapted to be loosely adapted extended. The housing II has disposed therein an annular jaw carrier l8 which is formed with a plurality of inclined openings l9 through which inclined jaws or work gripping members 20 are to slidingly engage.

The jaws 20 are formed at their inner ends with rounded end portions 2| for engagement with the periphery of the work l1 and each jaw 20 includes a rounded head 22 offset from the outer end of the jaw 20 by means of a reduced diameter shank 23. A spring 24 engages about the jaw 20 and bears at its outer end against the head 22 to thereby constantly urge the jaw 20 outwardly to work releasing position.

The jaw carrier I8 is formed integral with a disk-shaped plate 25 which has extending inwardly therefrom a cylindrical member 26. The cylindrical member 26 is slidingly disposed in a cylindrical part 21 which is formed integral with and extends inwardly from the inner disk-shaped wall 28 of a tapered or frusto-conical jaw operator 29. The frusto-conical jaw operator 29 is loosely disposed within the cylindrical member l4 so that the jaw operator 29 may freely rotate within the cylindrical member i4.

The inner end of the jaw operator 29 includes an annular recess 30 within which the inner end of the jaw carrier I8 is adapted to loosely engage. A spring- 3| is disposed within the cylindrical member or sleeve 26, bearing at its inner end against the wall l2 of the housing H and bearing at its outer end against the wall -or plate 25 which is formed integral with the carrier 18. The cylindrical member or sleeve 21 is snug-1y disposed within the inside of an inner anti-friction race 32. An outer race 33 engages the inside of the cylindrical member l4 and the anti-friction members 34 are interposed between the two races 32 and 33 and in the present instance these anti-friction members 34 are constructed in the form of rollers.

In the use and operation of this chuck, the shank or spindle I0 is inserted in the tapered bore of the tail stock. The end of the work I1 is inserted through the opening it of the cap l5 so that it will engage within the work carrier [8. The work I! will force the jaw members 20 outwardly in a radial direction and will also force these jaw members outwardly toward the large end of the jaw operator of compressor 29. The jaws 20 may. be firmly engaged or gripped to the work H by moving the tail stock endwise in the direction of the work. This movement of the tail stock will cause the carrier l8 to be moved inwardly of the housing II and as the carrier l3 moves inwardly the jaws 28 will be moved radially toward the work 17, riding at their outer ends on the inner frusto-conical surface of the jaw compressor or operator 29.

By providing the anti-friction bearing for the jaw operator, the work I! can freely rotate relative to the housing ll. With a construction as hereinbefore described, the work will be automatically centered relative to the axis of the tail stock spindle and the spindle of the head stock and at the same time it will not be necessary to provide a center hole in the work as is customary where a center point is used with the work. The outer wall of the cap l will provide a limit or, stop 'means for limiting the outward movement of the jaw carrier I8 underthe tension of the surface against which said jaws are adapted to engage whereby endwise movement of said carrier will thereby eifect radial movement of said jaws, and springs constantly urging said jaws to engage said surface.

2. In a chuck having a shank and a housing fixed to and extending coaxially of one end of said shank, a jaw carrier in said housing, means mounting said carrier in said housing for combined endwise and rotary movement, a plurality of radially disposed cylindrical work gripping jaws slidable in said carrier, said carrier including an inner wall against which the work is adapted to engage to thereby move said carrier endwise and inwardly of said housing, a spring constantly urging'said carrier outwardly of said housing, a

spring 3|. The springs 24 will maintain the jaws in contact with the inner surface of the compressor or operator 29 as the carrier I8 moves outwardly under the tension of the spring 3|.

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claims.

What I claim is:

1. In a chuck having a shank and a housing fixed to and extending coaxially of one end of said shank, a Jaw carrier in said housing, means mounting said carrier for combined endwise and rotary movement, a plurality of radially disposed cylindrical work gripping jaws slidably carried by said carrier, said carrier including an inner wall against which the work is adapted to engage to thereby move said carrier endwise and inwardly of said housing, a spring constantly urging said carrier outwardly of said housing, a jaw operator in said housing formed with a Irusto-conical inner jaw operator in said housing formed with a frusto-conical inner surface against which said jaws are adapted to engage whereby endwise movement of said carrier will thereby efiect radial movement of said jaws, and anti-friction means in said housing correlated with said jaw operator.

FENTON KRAEMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,235,957 Bidwell Aug. 7, 1917 1,565,227 Garrison Dec. 8, 1925 1,806,344 Goad May 19, 1931 FOREIGN PATENTS Number Country Date 50,205 Germany Jan. 2, 1890 

